N/A STATEMENT REGARDING FEDERALLY
N/A SPONSORED RESEARCH OR DEVELOPMENT
The present invention relates to industrial control systems and in particular to an operator interface used in industrial control systems.
Industrial controllers are special purpose computers used for controlling industrial processes or manufacturing equipment. Under the direction of a stored program, the industrial controller examines a series of inputs reflecting the status of the controlled process and changes outputs affecting the control of the process. The inputs and outputs are most simply binary, that is xe2x80x9conxe2x80x9d or xe2x80x9coffxe2x80x9d, however analog inputs and outputs taking on a continuous range of values are also used. The binary inputs and outputs may be represented by single bits of data, the analog inputs and outputs may be represented by multiple bit data words.
In one common architecture for industrial controllers, a central processor reads and writes input and output values from and to an I/O image table. The I/O image table in the controller collects the values of all inputs and outputs of the control system where they may be rapidly accessed by a control program, also executing on the central processor, without the need to be concerned with complex communication protocols used to exchange data directly with the I/O modules. Normally, separate circuitry operating asynchronously to the processor refreshes the I/O image table by communicating with one or more I/O modules in a scanning process. Thus, the I/O image table simplifies and speeds the execution of the control program.
The I/O modules may be distributed about a factory to be near the machinery with which they communicate and are joined to the central processor via a high speed network as is known in the art. Typically, also linked to the high speed network are one or more human/machine interfaces (HMIs) displaying the status of critical process variables to human operators. The HMI may be a display only, for example a plasma or LED panel, or an entire computer terminal and may allow both for the display of data and for input by a human operator. Input from the operator may be used to reprogram aspects of the particular piece of equipment or to communicate with the central processor.
In advanced control systems, an HMI may be associated with each machine or group of machines.
One advantage to an integrated control system employing a control network interlinking all machines and the central processor is that the process may be readily monitored from a single location. Nevertheless, as a practical matter, it is still desirable and necessary for human operators to tour the physical plant facilities for the purpose of process monitoring and during the installation or modification and troubleshooting of the control system. Traditionally, such operators carry with them test equipment such as voltmeters and the like, but increasingly, these are giving way to software tools run on a portable computer and connecting to the network. Such software tools are cumbersome to use requiring a computer to be carried about and requiring repeated input from the operator to direct the software tools to the relevant data associated with the particular machine.
What is needed is a more sophisticated software-type tool for industrial control systems providing the simplicity and intuitive nature of a voltmeter or other physical tool.
The present invention provides one or more virtual software tools that may be accessed on the HMIs already distributed about a factory. The tools execute independent of the HMI under the control of a processor located arbitrary on the network.
In the preferred embodiment, each HMI includes means for passively identifying the presence of the operator in the vicinity of the HMI so as to send a signal to the processor executing the tool program to display the necessary information at the HMI where the operator is present. The operator may provide inputs through the HMI to interact with the tool and the tool program may automatically be configured to receive data relevant to the particular location where the operator is located.
Thus, the virtual tool may follow the operator about the factory from HMI to HMI without interruption in its operation or in the operation of the conventional duties of the HMI which may be performed in a background window or the like. That is, the tool application need not be restarted at each HMI. Further the tool may automatically connect itself to the local machines by identifying relevant data typically in the I/O table of the processor executing the tool program.
Specifically, the present invention provides an industrial control system for controlling the operation of a process executed on a plurality of machines distributed in a factory. The control system generally includes a data network, and a plurality of machine interface circuits joined by the data network providing output signals to the machines and receiving input signals from the machines, and a plurality of operator terminals, also on the data network, providing terminal outputs to human operator. The operator terminals have operator identification means for producing an operator identification signal identifying a human operator using, or in the proximity of, the operator terminal. An electronic computer communicates with the interface circuits and the operator terminals over the data network to execute a control program to read the input signals from the machine interface circuits and to generate output signals to the machine interface circuits based on the input signals and the control program. The electronic computer further executes a tool program based on received operator identification signals to generate first terminal outputs. Finally, the computer executes a routing program to redirect first terminal outputs to a particular operator terminal with movement of the operator to the particular operator terminal as indicated by the operator identification signals without interruption of the execution of the tool program.
Thus, it is one object of the invention to provide a virtual tool box of one or more software programs that may follow an operator about in a factory environment without interruption of the execution of the tool program such as would interrupt the operator""s work flow.
The electronic computer may hold a number of operator programs related to different classes of operators and the operator identification signal may be used to designate a particular operator program for execution based on a known class of the operator.
It is yet another object of the invention to allow custom tool boxes to be identified to particular operators so that the appropriate tools are displayed on a given HMI depending on the role assigned to the individual. In this way, a suite of appropriate applications may follow an operator about the factory.
The electronic computer may further execute a machine program to generate second terminal outputs based on machine interface signals related to a given machine associated with a particular operator terminal. The routing program also directs the second terminal outputs to the particular operator terminal. The first terminal outputs and second terminal outputs may be displayed on the particular operator terminal as separate portions of an operator terminal display screen. Each portion of the display may operate in a separate window as is understood in the art.
Thus, it is yet another object of the invention to allow dual use of the HMIs about the factory floor, both for their traditional status reporting tasks and to support the tool programs of the present invention.
The particular operator terminal may be associated with a given machine and the tool program may produce first terminal outputs to the particular operator terminal based on signals of the machine interface circuit associated with the given machine.
Thus, it is yet another object of the invention to allow both seamless transition of tool programs between HMIs distributed about the factory and to further facilitate the use of software tools that require particular machine associated data, based on the context of their use. Thus, for example, just as a voltmeter accepts arguments of the voltages of a particular machine near the operator, tool programs may automatically take as their arguments data associated with the machine at hand rather than the process as a whole.
The tool program may also produce the first terminal outputs to the particular operator terminal based on portions of the control program associated with the given machine.
Thus, it is another object of the invention to provide a convenient tool for use by programmers allowing them to view relevant code associated with the machine they are near.
The foregoing and other objects and advantages of the invention will appear from the following description. In this description, references are made to the accompanying drawings which form a part hereof, and in which there are shown by way illustration, the preferred embodiment of the invention. Such embodiment does not necessary represent the full scope of the invention, however, and reference must by made therefore to the claims for interpreting the scope of the invention.